1. Technical Field
The present invention relates to a liquid ejecting head including a piezoelectric element which causes a pressure change in a pressure generation chamber communicating with a nozzle opening and has a piezoelectric layer and an electrode that applies a voltage to the piezoelectric layer, a liquid ejecting apparatus, and the piezoelectric element.
2. Related Art
As a piezoelectric element used in a liquid ejecting head, there is a piezoelectric element configured by interposing a piezoelectric layer made of a piezoelectric material that presents a electromechanical conversion function, for example, a crystallized dielectric material between two electrodes. Such a piezoelectric element is mounted in the liquid ejecting head as, for example, an actuator device in a flexural vibration mode. Here, as a representative example of the liquid ejecting head, for example, there is an ink jet type recording head in which a part of a pressure generation chamber communicating with a nozzle opening that discharges ink droplets is configured as a vibration plate, and the vibration plate is deformed by the piezoelectric element to pressurize ink in the pressure generation chamber, thereby discharging the ink as ink droplets from the nozzle opening.
A piezoelectric ceramic film included in the piezoelectric element requires high piezoelectric characteristics, and as a representative example of the piezoelectric material, there is lead zirconate titanate (PZT) (refer to JP-A-2001-223404). However, since lead zirconate titanate contains lead, from the viewpoint of environmental problems, a piezoelectric material that does not contain lead is required. Consequently, as the piezoelectric material that does not contain lead, for example, piezoelectric materials having a perovskite structure based on bismuth ferrite (based on BiFeO3) containing bismuth and iron are suggested. As a specific example, there is a composite oxide represented as a mixed crystal of bismuth ferrate manganate such as Bi(Fe,Mn)O3 or barium titanate such as BaTiO3 (for example, refer to JP-A-2009-252789).
The bismuth ferrite-based piezoelectric material has a problem in that cracks are more likely to occur, compared to the piezoelectric layer made of the piezoelectric material containing lead. In particular, there are problems in that cracks are more likely to occur when a thick piezoelectric layer (for example, a piezoelectric layer of equal to or greater than 750 nm) is formed and it is difficult to form a thick piezoelectric layer made of a bismuth ferrite-based material.
In addition, of course, such problems occur not only in the ink jet type recording head, but also in other liquid ejecting heads that discharge liquid droplets other than ink, and also occur in piezoelectric elements used for devices other than the liquid ejecting head.